Locking device



Marh 28, 1939. G. w. JAcoBsoN LOCKING DEVICE Filed March 25, I19255 f Patented Mesas, 1939 UNITED STATES G'unnard W. Jacobson,

Chicago, Ill., assgnor to Illinois Tool Works, Chicago, Ill., a. corporation of Illinois Application March 25,

3 Claims.

My invention relates generally to locking' devices, and particularly to a clamping member and lock washer assembly.

It is one of the important objects of my in- 5 `vention to provide a clamping member and lock washer assembly wherein a pronged washer of the internal tooth type may be conveniently retainedv plates lock Washers of the `type mentioned above equipped with laterally extending gripping elements which are adapted to resiliently bear against the peripheral structure of the clamping 25 member, and at the same time permit relative rotation between the washer and nut during the clamping operation.

'Ihe foregoing and numerous other objects and advantages will be more apparent from the folwhereinv Figure 1 is a side elevational view of a nut and washer assembly which is representative of one embodiment of my invention; v

Figure 2 is a central vertical sectional view take; substantially along the line 2-2 of Figure Figure 3 is a horizontal sectional view of the underside of the assembly shown'in Figure 1, said view being taken substantially along the line 3-3 of Figure 1; I

Figure 4 illustrates the manner in which the washer maybe economically stamped from fiat spring stock;

Figure 5 illustrates a'modiiled nut and washer assembly whereby the nut or clamping member is provided with an annular structure which coopcrates with the gripping elements of the washer in maintaining said parts together as an operative unit; anld Figure 6.discloses a still further modication wherein' the threaded clamping member is provided with a cylindrical surface against the 55 outer peripheral surface of which the gripping Still more specifically, my invention contemlowing detailed description when considered in connection with the accompanying drawing,

1935, serial No, 12,779

elements of the washer are adapted tobear, the cylindrical outer surface of the clamping member serving to render the parts relatively'rotatable as the ass'embly is being tightened against a workpiece. In both Figures and 6 a portion of the washer is broken away to more clearly illustrate the manner in which the gripping elementscooperate with the peripheral surface of the clamping member. Y

Referring now to the drawing more in detail wherein like numerals have been used to designate similar parts throughout the various'iigures, it will 'be noted that Figure 1, illustrating one embodiment of my invention, includes a lock Washer I0 coupled with a rotary clamping member or nut I2. The nut I2 is threaded to receive a screw or bolt I4, and by rotating the nut in a clockwise direction, as viewed from above, said nut and washer assembly may be .tightened against the surface of a work piece I6.

The washer IIJ is preferably stamped, or otherwise formed, from flat spring stock-for example,

the strip stock I8 shown in Figure 4. The washer includes an annular body portion 2li and a plurality of internal marginal prongs 22 which are warped or bent in such a manner as to present oppositely disposed work engaging edges or corners. Extending laterally of and formed integral with the annular body 20 are a plurality of grippingy elements 24 designed to impinge or yieldingly grip a complementary peripheral surface 26 of the nut I2. In Figures li-to 3, inclusive, this surface 26 is slightly inclined withrespect to the axis of the clamping member or nut l2 and is formed by providing a radially exposed annular opening 28. The portion of the nut stock bounded by the peripheral surface 26 has a clamping surface 30 which is adapted to bear against and lockingly engage the washer prongs l22 when the nut is'tightened upon the screw or bolt I4. The gripping elements 24 when ldetached from the nut I2 occupy the dotted position indicated in Figure 2. Thus, after the washer has been urged into its normal operating position, the elements 24 are sprung outwardly as a result of the/impingement thereof with the surface 26, and in this manner said gripping elements yieldingly bear against and thus frictionally engage the surface 26. The frictional resistance thus set up is suiicient to positively prevent inadvertent axial displacement of the clamping member and washer, but will permit relative rotation between said parts when the nut causes the washer prongs 22 to engage the work piece I6. In other words, after the assembly comprising the nut and washer has been shifted 'into operative engagement with the work, theedges of the prongs on one side of the washer will lockingly engage the work and set up suficient resistance to prevent rotation of the washer with respect to the work. 'I'he nut or clamping member is then free to complete its rotary clamping movement. This continued clamping movement of the nut places the washer prongs 22 under tension,and thereby establishes an effective interlock between the work and the nut.

I have been able to reduce .waste of material inthe strip stock I8 by circumferentially disposing the gripping elements 24 about the body 2li in the manner indicated in Figure 4. -It will be seen that two of the gripping elements, which I have indicated by the numeral 24a in Figure 4, are spaced closer to each other than they are to the element I have designated as 24h. If the elements were equally spaced about the body and then stamped from the strip stock I8, a considerable increase in waste material would be experienced. By having the unequal circumferential spacing of thev gripping elementso as just described, scrap is reduced to a minimum.

In Figure 5 1 have shown a modified assembly wherein the washer Ill is identical in structurel with the washer just described. A nut |2114 is shown which is provided with an annular flange 32. The gripping elements 24 resiliently grip or bear against the ilange 32 in the same manner as they impinge the peripheral surface "26 shown in Figures 1 to 3, inclusive. As the assembly :is being clamped against the Work, the frictional resistanoe'set up between the gripping elements l24 and the flange 32 is overcome to the extent From the foregoing it will be apparent that my invention contemplates a simple and ,practical nut and washer assembly wherein the washer is maintained in operative position'on the clamping member by resiliently gripping an exposed peripheral surface, the friction set up by the gripping actionof the washer being insuiicient to preclude relative rotation between the parts during the clamping operation. Obviously the in-` vention is -not limited to clamping members in the form 'of nuts disclosed herein, but is adaptable to screw heads and other types of threaded devices equipped with clamping surfaces. My

Y improved lock washers equipped with the gripping elements can be produced from iiat spring stock with a minimum amount of waste material, and this is bf the greatest importance from the standpoint of economy in production. While the amount of waste stock or scrap for each iwasher in itself may seem small, in the aggregate the total cost for such waste becomes a vital factor.

Having thus described my invention, what I claim as new and' desire to secure by Letters Patent is:

1. A locking device including'a rotary clamping member having a clamping surface and an annular iiange encircling the outer periphery of the clamping member, a lock washer formed of spring stock, said washer including an annular body portion and a plurality of internal marginal resilient prongs warped out of the plane of the body, and means extending axially of the washer body and yieldably bearing against the flange of said clamping member for securing the washer and clamping member together as a unit and permitting relative rotationbetween the washer and clamping member as said parts are tightened against a work piece, theprongs of said washer being operatively associated with the clamping surface of said rotary clamping member, the bounding planes of said annular body being perpendicular to the axis of the washer prior to the application of said washer to the work. n

2.- A locking device including a rotary' clamping member having a clamping surface and an outer periphery comprising a single, curved, concentric, smooth surface encircling the clamping member, a lock washer formed of springmember together as a unit and permitting relative rotation between the washer and clamping member as said parts are Vtightened against a work piece, the prongs of said washer being op'- eratively associated with the clamping surface' of said rotary clamping member, said` prongs, an-l nularybody, and yield'able bearing means extendving from said bodyubeingonstructedy and ar-` ranged whereby to prevent radial movement of the prongs when the washer is clamped against a work piece.

3. A locking device including a rotary threaded clamping member having a clamping surface and an outer periphery, said outer periphery comprising seat means located substantially concentrically about the axis of said rotary clamping member and adapted to provide an outer seating portion for interengagement with a laterally extending portion of a lock1 Washer, and a lock washer, said washer including an annular body portion and a plurality of internal, resilient teeth projecting in opposite directions out of the plane of said body portion, said washer body being provided in the vicinity of its outer margin with flange means extending axially and adapted to clamping member for securing the lock washer andthe clamping member together as a unit and permitting relative rotation between the lock washer and clamping member as the. parts are tightened against a work piece, the resilient teeth of said washer being operatively associated'with the clamping surface of said rotary clamping member, said teeth, 'annular bodyand said axially extending ange means being constructed and arranged whereby to retain the lock washer in a position substantially co-axial with the clamping member when' the washer is tightened against a work piece.

GUNNARD w. .JAcoBsoN.

` engage said outer peripheral seat means of the 

